The geothermal analog of pumped storage for electrical demand load following
- Los Alamos National Lab., NM (United States). Earth and Environmental Sciences Div.
A 6-day cyclic Load-Following Experiment, conducted in July 1995 at the Los Alamos National Laboratory`s Fenton Hill Hot Dry Rock (HDR) test site in north-central New Mexico, has verified that an HDR geothermal reservoir has the capability for a significant, and very rapid, increase in thermal power output upon demand. The objective of the Load-Following Experiment was to study the behavior of the Fenton Hill HDR reservoir in a high-production-backpressure (2,200 psi) baseload operating condition when there was superimposed a demand for significantly increased power production for a 4-hour period each day. In practice, this enhanced production--an increase of about 65%--was accomplished by a programmed decrease in the production well backpressure over 4 hours, from an initial value of 2,200 psi down to about 500 psi. This rapid depressurization of the wellbore during the period of enhanced production resulted in the draining of a portion of the fluid stored in the pressure-dilated joints surrounding the production well. These joints were then gradually reinflated during the following 20-hour period of high-backpressure baseload operation. In essence, the HDR reservoir was acting as a fluid capacitor, being discharged for 4 hours and then slowly recharged during the subsequent 20 hours of baseload operation. In this mode of operation, there would be no increase required in the reservoir size or number of wells for a significant amount of peaking power production for a few hours each day. Therefore, one of the advantages of geothermal load following over other utility options such as pumped storage or compressed air energy storage is that the HDR power plant would be operated during off-peak hours in a baseload mode, with an augmented return on investment compared to these other peaking systems which would normally not be operated during off-peak periods.
- OSTI ID:
- 435576
- Report Number(s):
- CONF-960805--
- Country of Publication:
- United States
- Language:
- English
Similar Records
Experimental verification of the load-following potential of a Hot Dry Rock geothermal reservoir
Experimental verification of the load-following potential of a hot dry rock geothermal reservoir